Improvement in direct-acting engines



UNITED STATES PATENT Orton.

GEORGE F. BLAKE, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN DIRECT-ACTING ENGINES.-

Specification forming part of Letters Patent No. 60,852, dated January 1, 1867.

To all whom it may concern Be it known that I, GEORGE F. BLAKE, of the city of Boston, in the State of Massachu setts, have invented certain new and useful Improvements in Steam Pumps; and I do hereby declare the following to be a full and correct description of the same, reference being had to the accompanying drawings, in which- Figure l is a longitudinal vertical central section'of the engine and pump, looking toward the left side. Fig. 2 is a similar section, looking toward the right side. Fig. 3 is a horizontal section on the line u u of Figs. l and 2. Fig. 4 is a transverse vertical section on line v v of Figs. l and 2. Fig. 5 is a similar section on line w w of said figures. Fig. 6 is a similar section on line w of the same. Fig. 7 is a similar section on line y y of the same. Fig. 8 is a similar section on line z z of the same. Fig. 9 is a perspective view of the plun` ger of the upper cylinder; and Fig. l() is a similar view of the valve, which is operated by said plunger.

The same part is marked by the same letterof reference wherever it occurs.

The nature of this invention consists in the method herein described of operating the slidevalve of a steam-pump by a device which allows the steam-cylinder and pump-cylinder to be brought nearer together than would be possible if the valve were operated directly by the piston-rod, thus diminishing the weight of the machine, and rendering it more compact, convenient, and portable.

It further consists in providing the upper cylinder with an independent exhaust, which also serves' as an auxiliary exhaust for the main cylinder, facilitating the rapid discharge of steam from the exhaust end ofthe cylinder, promoting quick action of the piston, and, by the prompt taking of steam when the piston nears the end of its stroke and by a peculiar method of cutting off,77 preventing the pounding of the piston against the cylinder-heads, which is so common and so injurious in steampumping engines.

To enable others to make and use my improved steam-pump, I will proceed to describe its construction and operation, referring to the drawings, whereon- A marks the pump-cylinder B, the pump piston; C, the piston -rod, common to the pumppiston B, and the steam-piston D, which moves in the steam-cylinder E. F is a tappetrod,'which extends from one cylinder to the other, as shown in Fig. 2, moving freely, but steamtight, through the stufling-boxes c d, in obedience to impulses received alternately and at intervals from the pistons B and D. Attached, by a slotted joint, to the tappet-rod is a swinging lever, G, which is pivoted at g to the stationary standard I. 'lo this lever is also pivoted, through a slot at f, the valverod H, which passes into the steam-chest J through the stufngbox h. K marks the main inlet-port, and L the main exhaust-outlet. M is the small slide-valve, and N the main slide valve, which is iixed in and slides with the cylindrical plunger O in the small upper cylinder P. The valve M is a flat slide-valve ofthe ordinary kind, having two cups, t t. It controls the ports which supply and exhaust the upper cylinder P, and also the auxiliary exhaust-ports of the main cylinder. The valve N (see Figs. l, 2, and l0) is a segment of a cylinder, and controls the supply and exhaust ports of the main cylinder, and also, in conjunction with valve M, acts as a cutoff, as will be hereafter explained. Its form is clearly shown in the drawings, and it will be observed that its plain surface projects at either end some distance beyond the cups a. and b. I

The plunger O (see Fig. 9) is a hollow cylinder with solid ends, open at top and bottom, and with slots d in its sides to receive a pin, e', which allows it reciprocating motion in the cylinder P, but prevents it from turning on its axis. The valve N is received into thc lower opening of the plunger P, and moves with it. Steam-passages c c lallow the free circulation of steamparound the plunger, and thus equalize the pressure on the valve N, and lessen its tendency to wear.

The steam-ports are marked j It l m up q i' s t u. Of these j leads from the steamchest to the rear end of the cylinder P. k is the exhaust for cylinder P and the auxiliary exhaust for the main cylinder, communicating, as seen in Fig. 3, with passage R leading to exhaustoutlet L. l connects the steam-chest with the steamway n' leading to the rear end of the main cylinder, and serves to connect that steamway with the auxiliary exhaust k. m is the supply-port for the rear end of cylinder E. a is alternately the supply and exhaust of the same end of. that cylinder. p is the common exhaust for both ends of the main cylinder, and communicates direct-ly with the steamoutlet L.

The ports on the forward end of the steamchest have a corresponding arrangement and functions to those on the rear end, already described. q corresponds with n, r with m, s with Z, t with k, and u with j.

The ports controlled by slide-Valve M are those marked j h l m and r s t u, and those controlled by the valve N are those marked m a p g r. The ports common to the two valves are those marked m and r.

The course ot' the steam is as t'ollows: When the valve M is in the position shown in Fig. 3, steam passes through port m u nder valve N, through port n and passage n', into the rearJ ward end ot' cylinder E, driving the piston D toward the forward end of the cylinder. At the saule time the exhaust takes place through passage q', port q. under valve N, through port p and outlet L. 'lhe auxiliary exhaust also takes place simultaneously through port s, un-

der valve M, and through port t, into steamway It, and out at main outlet L, thus facilitating the rapid discharge of steam from the forward end ofthe cylinder. When piston I) has moved forward far enough to strike the tappet-rod F, portj is uncovered by valve M, and the rear end ot' the cylinder P takes steam through passage j', and under the spring-Valve o in the rear'end ot' the cylinder, the valve c opening under the pressure of the steam. The plunger 0 is driven forward, the steam `in front ot' it exhausting through ports u and t, which are connected by valve M'. The forward end ot' the main cylinder then takes steam through ports t' and q, which are connected by Valve N, port 'r being .uncovered by valve M, for the passage of steam from the steam-chest. The main exhaust of the rear end oft-he cylinder takes place through ports n and p, connected by valve N, and the auxiliary exhaust of the same end is through ports t and 7c, connected by valve M.

When the piston D is moving forward from the rearward end ot' its stroke, the plunger O remains in the position shown in Figs. l and 2 until the piston has advanced t'ar enough to strike the tappet-bar F and change valve M, so that it shall uncover portj, and let the cylin der P take steam at its rearward end through that port. The plunger O is then driven forward, the steam in front of it exhausting through ports u and t, connected by valve M. When the plunger has passed forward far enough to cover the upper opening of port u, the valve c closing by the pressure of steam upon it, the plunger cushions onthe stratum of steam inclosed in the space between the upper end of lport; u and the cylinder-head.

The valve N not only serves to regulate the supply and exhaust of the main cylinder in the ordinary way, but co-,operates with valve M in t'ormin g a cut-oft'. The valve being prolonged at the ends beyond the cups a' b', those prolongations serve, at a proper period .of the stroke, as a cut-oit' by preventing the flow of steam through the supply-ports fm, and r, alternately, to the ends ofthe main cylinder, with which those ports, respectively, connect. In the drawings this valve is shown as thus closing the upper end ol' port r, while the lower `end of the same port is closed by valve M. Thus, before the piston gets to the end ot' its stroke, the supply of steam behind it is cnt ott', and that end of the cylinder put in communication with the auxiliary and main exhaust ports. In this way the objectionable pounding of the piston against the end of the cylinder is avoided, and the piston is caused to respond quickly to the changes of the valves.

Having thus fully described my invention, what'I claim, and desire to secure by Letters Patent, is-

l. The tappet-rod F, arranged as described, for the purpose specified.

2. The combination of the rod F, lever G, and valve-rod H, substantially in the manner described.

3. The auxiliary exhaust, arranged and operating substantially as specified.

4. So controlling the supply-ports of the main cylinder, by the conjoint action of valves M and N, that those valves shall together constitute a cut-off to arrest the supply ot' steam to either end of the main cylinder, while that end is exhausting, substantially in the manner and for the purpose set forth.

The above specifica-tion of my said invention signed and witnessed at Boston this 13th day of August, A. D. 1866.

GEORGE F.- BLAKE.

Witnesses:

(JH/ls. RASTANSBURY, SAML. W. BATES. 

